When buying a television, aside from the price, the first thing we pay attention to is undoubtedly the quality of the picture.As the main component of a TV, the screen accounts for over 60% of the total cost.For a long time, the idea of “looking at the screen first when buying a TV” has been widely spread among the public.

So, do you know what types of TV screens there are?Currently, the frequency of updates in the TV market is getting faster and faster, with many new categories launched by both domestic and joint venture brands.Technologies like OLED and QLED… have once again sparked the buying desire of consumers.

There are currently too many panel types and screen technologies; not only ordinary consumers but even professional players can easily get confused. Today, we will summarize this in a simple way.

In fact, the mainstream screen materials in the market are divided into two categories:LCD (Liquid Crystal Display) and OLED (Organic Light-Emitting Diode). It is generally believed that OLED is technically more advanced than LCD. However, although OLED is gaining popularity, it is still limited by price, so LCDs are relatively more common.

■First, let’s take a look at LCD

LCD is what we usually refer to as liquid crystal.It requires backlight support to display content, and the backlight must pass through glass, color filters, optical films, substrates, and alignment films to generate polarized light, inevitably resulting in some loss in color and brightness.What we usually call TFT stands for Thin-Film Transistor.In LCDs, TFT is deposited as a thin film on the glass substrate to serve as a channel area to improve imaging quality. The upper glass substrate is placed next to the color filter, while the lower glass substrate is embedded with transistors.

LCD Display Principle

When current passes through the transistor, it generates a change in the electric field, causing the LCD molecules to deflect, changing the polarization of light, and then using polarizers to determine the brightness of the pixels.At the same time, the color filter that is affixed to the upper glass forms the R, G, and B primary colors contained in each LCD pixel, which constitutes the image displayed on the screen.

■Having briefly discussed LCD, let’s talk about panel types

TN panel stands for Twisted Nematic, which is one of many panel types.Due to its low production cost, TN has become the most widely used entry-level panel. Currently, mainstream mid-range and low-end LCD TVs or monitors on the market mostly use TN, and early flat screens and mobile phones also often used it.Many users now equate TN with TFT, which is actually a conceptual confusion.

TN Display Principle

Due to the maturity of TN technology and its low cost, it is still favored by some low-cost products.Additionally, TN panels with high opening rates consume less power at the same brightness, and their response speed of 8-15ms is relatively fast.Therefore, despite the disadvantages of color distortion and narrow viewing angles, TN has not faded from the market.

VA panel stands for Vertical Alignment, which is now more commonly used in high-end LCD applications and belongs to wide-angle panels.VA includes Fujitsu’s MVA and Samsung’s PVA, with the latter being an improvement and continuation of the former.Compared to TN, VA has higher contrast, clearer and sharper text display, and can provide wider viewing angles and better color reproduction. The drawbacks are higher power consumption and cost, and VA is considered a soft screen, which can produce ripples when lightly touched.

VA Display Principle

MVA stands for Multi-domain Vertical Alignment, a multi-quadrant vertical alignment technology developed by Fujitsu, which has been produced under technology licensing by companies such as Chi Mei Electronics and AU Optronics.However, after the financial crisis, manufacturers of wide-angle panels encountered difficulties.Chi Mei and AU Optronics found MVA to be costly and low in profit, so they stopped supplying display manufacturers.Meanwhile, LG and Samsung, with their market insight, took over the market previously held by MVA with C-PVA and E-IPS, which are priced similarly to TN.

MVA features excellent performance in viewing angles, color, and color gamut, significantly better than regular TN, but the drawback is a slightly slower response time. However, the improved P-MVA can achieve a viewing angle close to 178° and a response time of below 8ms.

PVA stands for Patterned Vertical Alignment, which belongs to the VA category and is the successor and pioneer of MVA, with comprehensive qualities that have surpassed MVA.The improved S-PVA can even rival P-MVA, achieving extremely short response times and extremely wide viewing angles.

PVA uses transparent ITO electrodes to replace the protrusions in MVA, allowing for better opening rates, minimizing waste of the backlight, and reducing the possibility of “bright spots” in LCDs. Its status in the LCD era is comparable to that of CRT in the CRT era.

IPS stands for In-Plane Switching, a wide-angle technology introduced by Hitachi in 1996.It effectively improves the poor viewing angles and color differences of TN.IPS can achieve nearly 180° viewing angles, greatly improving the shortcomings of TN.

IPS Display Principle

In 1998, Hitachi launched S-IPS, which not only retained the original advantages of IPS but also improved response speed.In 1999, LG-PHIHIPS joined the IPS camp as a joint venture and after declaring bankruptcy in 2006, the IPS business was mainly managed by LG Display.

During this period, in 2002, Hitachi launched AS-IPS, which made significant improvements in contrast.That same year, Hitachi also introduced IPS-PRO, which was specifically divided into E-IPS, H-IPS, and S-IPS.

Hitachi

E-IPS is considered the economic version of H-IPS, with slightly poorer contrast and color but achieving 72% color gamut, and the reduction in opening rate improves the viewing angle.

H-IPS (Horizontal IPS) is most notably distinguished by changing the fish scale pixel arrangement of S-IPS, with each pixel arranged in a straight line, forming a continuous line from top to bottom, with smaller electrode widths between each pixel.

Compared to S-IPS, H-IPS slightly improves contrast and color performance and is relatively more expensive, while S-IPS has good cost performance due to its lower price.

Later, LG Display, which took on the responsibility of IPS, launched AH-IPS in 2012, which made significant upgrades in contrast, power consumption, and other aspects, greatly enhancing display quality.

LG Display

With continuous technological advancements, a type of display with even better performance called AIPS has emerged, optimizing brightness and clarity.AIPS differs from IPS in that it does not pre-orient the LCD molecules to be in a transparent state but in an opaque state; the amount of light passing through is determined by the electrodes perpendicular to the orientation direction of the LCD molecules. The higher the voltage, the more LCD molecules are twisted, allowing for precise control of light.

AIPS only controls one deflection angle of the LCD, and the number of deflected molecules can be nearly proportional to the voltage, making it easier for LCDs to achieve layered control. The increase in dynamic contrast also enhances the performance of moving images.

IPS advantages include low price, high viewing angle, and accurate color reproduction, while the downside is that the purity of black is not sufficient, slightly worse than PVA, thus requiring optical film compensation to achieve purer black.IPS screens are relatively “hard” and do not easily produce ripples when touched, which is what we commonly refer to as “hard screens.”

■Finally, let’s take a look at OLED

OLED stands for Organic Light-Emitting Diode, which, unlike the previously mentioned LCD, does not require backlight support.OLED is an innate surface light source technology, emitting light in red, green, blue, and white monochrome, achieving full-color effects, and belongs to a brand new light-emitting principle.The reason why plasma technology, OLED technology, and even the picture quality of early CRT technology are praised is mainly due to their characteristic of “self-emission.”

OLED technology can turn off individual pixels, bringing their brightness to zero.Theoretically, the contrast ratio of OLED technology can reach infinity.Therefore, OLED cannot exhibit light leakage in dark scenes, thus enhancing contrast and picture quality performance.

Additionally, since OLED technology does not require backlight support, it eliminates the need for liquid crystal and backlight modules, resulting in a very simple structure, and the body can achieve extreme thinness, approximately 1/3 the thickness of traditional LED screens.

OLED also features a flexible and bendable characteristic, which can be applied not only to televisions but also holds great potential for smart devices in the future.Combining the thin characteristics of OLED, screens can be made as thin as a piece of paper and can be bent and folded freely, which was unimaginable in the LCD era.

Finally, it is worth mentioning that whether it is LCD or OLED, they both have their significance as long as they exist.As consumers, we need not get lost in a pile of parameters; instead, we should try more and experience the real effects in stores to choose products that suit our eyes.